/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */
import { Event } from '../events/event.js';
import { BaseAgent } from './base_agent.js';
import { InvocationContext } from './invocation_context.js';
/**
 * A unique symbol to identify ADK agent classes.
 * Defined once and shared by all SequentialAgent instances.
 */
declare const SEQUENTIAL_AGENT_SIGNATURE_SYMBOL: unique symbol;
/**
 * Type guard to check if an object is an instance of SequentialAgent.
 * @param obj The object to check.
 * @returns True if the object is an instance of SequentialAgent, false otherwise.
 */
export declare function isSequentialAgent(obj: unknown): obj is SequentialAgent;
/**
 * A shell agent that runs its sub-agents in a sequential order.
 *
 * @deprecated Use `Workflow` instead, which expresses the same ordering as a
 * graph and adds routing, retries, HITL and resumability. This class will be
 * removed in a future version. Note that a `Workflow` cannot yet be an
 * `LlmAgent` sub-agent.
 */
export declare class SequentialAgent extends BaseAgent {
    /**
     * A unique symbol to identify ADK sequential agent class.
     */
    readonly [SEQUENTIAL_AGENT_SIGNATURE_SYMBOL] = true;
    protected runAsyncImpl(context: InvocationContext): AsyncGenerator<Event, void, void>;
    /**
     * Implementation for live SequentialAgent.
     *
     * Compared to the non-live case, live agents process a continuous stream of
     * audio or video, so there is no way to tell if it's finished and should pass
     * to the next agent or not. So we introduce a task_completed() function so
     * the model can call this function to signal that it's finished the task and
     * we can move on to the next agent.
     *
     * @param context The invocation context of the agent.
     */
    protected runLiveImpl(context: InvocationContext): AsyncGenerator<Event, void, void>;
}
export {};